Host processor systems may store and retrieve data using storage devices (also referred to as storage arrays) containing a plurality of host interface units (host adapters), disk drives, and disk interface units (disk adapters). Such storage devices are provided, for example, by EMC Corporation of Hopkinton, Mass. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels of the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical volumes. Different sections of the logical volumes may or may not correspond to the actual disk drives. The hosts, storage devices and/or other elements, such as switches and/or array components, may be provided as part of a storage area network (SAN).
In storage networks, and particularly storage networks including geographically remote access nodes and storage resources, preserving or reducing bandwidth between resources and access nodes is highly desirable as well as providing optimized data availability and access. Data access may be localized, in part to improve access speed to pages requested by host devices. Caching data at access nodes provides localization, however, it is desirable that the cached data be kept coherent with respect to modifications at other access nodes that may be caching the same data. An example of a system for providing distributed cache coherence is described in U.S. Patent App. Pub. No. 2006/0031450 to Unrau et al., entitled “Systems and Methods for Providing Distributed Cache Coherency,” which is incorporated herein by reference. Other systems and techniques for managing and sharing storage array functions among multiple storage groups in a storage network are described, for example, in U.S. Pat. No. 7,266,706 to Brown et al. entitled “Methods and Systems for Implementing Shared Disk Array Management Functions,” which is incorporated herein by reference.
Cloud computing technologies may provide for the use of online compute, network and storage services to execute applications in a virtual environment and in which resources may be efficiently allocated to provide on-demand compute and storage capacity over a network infrastructure. For discussions of systems and techniques for online services to provide on-demand data storage functions, see, for example, U.S. Pat. No. 7,836,018, entitled “Simultaneously accessing file objects through web services and file services;” US Patent App. Pub. No. 2009-0112811, entitled “Exposing Storage Resources with Differing Capabilities;” US Patent App. Pub. No. 2009-0112921, entitled “Managing Files Using Layout Storage Objects;” US Patent App. Pub. No. 2009-0112880, entitled “Managing File Objects in a Data Storage System;” and US Patent App. Pub. No. 2009-0112789, entitled “Policy Based File Management,” all to Oliveira, et al. and which are all hereby incorporated by reference.
It is noted that various issues may occur in connection with the management of resources using technologies like that discussed above. In particular, for example, processing and access of stored data, in particular large amounts of storage, may cause issues involving, for example, access times, processing costs and load balancing requirements among multiple data centers that are geographically dispersed and subject to varying levels of access demands depending on particular locations and/or particular times.
Accordingly, it would be desirable to provide an system that efficiently and effectively manages distributed storage to address issues like that noted above, particularly for a system in which resources are geographically dispersed.